Jamar Williams is looking for improvement today, and there's definitely room for it.

Williams got an opportunity to play with the starters last week when Hunter Hillenmeyer left early in the third quarter with a rib injury and Nick Roach moved from the strong side to the middle. Williams took over on the strong side but didn't make much of an impact with just 1 tackle.

"He did an OK job," coach Lovie Smith said. "Jamar has been a Will (weak-side) linebacker backing up Lance (Briggs) for the most part, but we got him a little bit of (practice) time at both of the outside positions. He did a pretty good job coming in. He was able to get a few more practice reps (this week) and that should only make him better."

With Hillenmeyer not expected to play Sunday, Roach would start at middle linebacker, and Williams would be at strong-side linebacker, just his second NFL start.

"It's a great opportunity for him," Smith said. "Jamar has stepped up in the past. We've talked about how good a football player he is for a while, but now it's time for him to prove it during the game."

And time is running out for Williams if he wants to be more than a special-teams standout, which he was last year when he had 15 tackles, second best on the team. After playing just three games as a rookie in 2006 before landing on injured reserve with a chest injury, Williams had a career-best 28 tackles in 2007, when he got his first NFL start. But last year he had just 1 tackle all season in limited play on defense and fell behind Hillenmeyer and Roach on the depth chart.

"I haven't started in awhile, but this is a big opportunity just to go out there and prove to the coaches that I can be a playmaker and get some more experience under my belt," said Williams, who is trying not to look too far ahead. "Just go out there and play and make something happen and at the end of the day let the cards fall where they fall."